If you after front linkage bush (No 20 in diagram) they the same as nx, n15 etc so quite easy find in US & Asia.
The bracket bush that gets swapped for solid mounting is easy fabrication job & if don't want solid mount can improvise with some poly in bracket design.
link below on bracket thread & similar topic to this one>
http://www.gtir-motorsport-club.com/t1745-how-to-have-a-better-feeling-with-the-standard-shifter
also linkage schematic & a solid bracket image for reference.
will add link for linkage bush when find decent price or UK direct source.
Expect most bits for full overhaul still available from nissan or custom made if needs be.
Heres an ebay search on what I think right for No20 linkage bush (energy suspension 7.1103)
http://www.ebay.co.uk/sch/i.html?_odkw=nissan+nx+shift+bushes&_from=R40|R40&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xnissan+nx+shifter+bushes&_nkw=nissan+nx+shifter+bushes&_sacat=0
They are 7USD direct in states :-/
http://www.gspec.com/p-832-shifter-bushing-set-b13-all-b15-18-20.aspx